1. Field of the Invention
The invention relates to amplifier circuit designs, and more particularly to a PSRR-enhanced output stage for amplifier circuit designs.
2. Description of the Related Art
Amplifiers are used for many applications including audio signal processing, video processing, communications, control systems, satellites, and so on. In low-power amplifier designs, the amplifier's Total Harmonic Distortion (THD) always degrades at high frequencies due to insufficient loop gain. Especially, when the output stage of the low-power amplifier suffers from noisy supply voltage, the noises generated from the supply voltage will finally present in the output signal, which results in undesired signal distortion.
Therefore, several novel amplifier designs with an enhanced Power Supply Rejection Ratio (PSRR) at the output stage are required.